WO1989008931A1 - Resistance welding method and resistance welding circuit device in lead acid battery - Google Patents

Abstract

This invention relates to a cell-to-cell resistance welding method for use in the production of a lead acid battery and to its circuit device. Conventionally, resistance welding between the lugs of cells has been made by a constant current control system or by a constant voltage control system. Therefore, the quantity of generated heat varies with a change in a contact area between the lugs during welding and stable welding cannot be obtained. Moreover, a spark is likely to occur at the start of welding to cause internal short-circuiting of the cell. The present invention solves these problems. The resistance welding method of the present invention is characterized in that resistance welding between cells and other portions is made by a constant power control system. The resistance value between members (e), (e) to be welded at the time of supply of power is measured by a resistance measurement device (11), the measured value is inputted to a constant power controller (13) and a current having a current value corresponding to this input value is applied to both members (e), (e). Namely, the present invention provides a method of performing these operations at a predetermined cycle and a circuit device (A) for this method, and stable and excellent resistance welding can be carried out in accordance with the present invention. An upslope controller (15) is incorporated in the resistance welding circuit device (A) so that resistance welding is performed with a current supply increased gradually from a smaller value to a larger value between both members (e), (e) and in this manner, the occurrence of the spark at the time of resistance welding can be prevented.

Description

 Specification

 Resistance welding method and resistance welding circuit device for lead-acid batteries

 The present invention relates to a resistance welding method and a resistance welding circuit device for a lead storage battery.

 Background art

 The resistance welding method between cells in a conventional lead storage battery is performed by a constant current control method or a constant voltage control method. That is, the ears of opposite polarity projecting upward from each end of the strap to which the ears of the electrode group assembled in each cell chamber of the lead storage battery are connected are connected to the adjacent cell chambers. A pair of resistance welding gages (electrodes) of the resistance welding apparatus are applied to the outer surfaces of the opposed strap ears and pressurized by applying pressure through the through holes provided in the partition wall for distinguishing the two. The ears are pressed against both sides of the partition wall, and the center of both ears is recessed into the through-hole with the projection of the gun. In this state, both guns are connected by the constant current control method or the constant voltage control method. It is common to carry out resistance welding between both ears, that is, so-called resistance welding between cells.

The conventional resistance welding method using the above constant current control method or constant voltage control method has the following problems. That is, the hardness of the strap ear varies, and the outer surfaces of both opposing ears are pressurized by a pair of guns (electrodes) having the projections. The center of both ears that are pressurized and come into contact with each other due to variations in Therefore, the amount of heat generated by the conventional energization by the constant current control method or the constant voltage control method is not constant as is apparent from the following equation. That is, in the constant current control method, since a current I is constant, if the mutual contact area between the electrodes pillars is relatively small, the electrical resistance值R size no longer, therefore the amount of heat Q = k I ₂ RT size It becomes. Conversely, if the contact area is relatively large, the electric resistance value R will be small, and thus the maturing Q will be very small.

On the other hand, in the constant voltage control method, since the voltage V = IR is constant, when the mutual contact area between the two ears is relatively small, the resistance value R increases, and the current decreases accordingly. Eventually, the amount of heat Q = kI · IRT becomes smaller. Conversely, when the contact area between the two ears is large, the resistance value R becomes small, so that the current value I becomes large, and the calorific value eventually becomes large. Thus, in the above various circumstances, Since there is a variation in the area of contact with each other when pressurized by the welding guns of both ears, stable welding cannot be obtained due to fluctuations in the amount of heat generated in resistance welding by the constant current control method or the blackout voltage control method. In some cases, poor welding is likely to occur. Further, in the constant current control method or the constant voltage control method, the following problems are involved in the energization process during resistance welding. In other words, in the constant current control method, at the start of energization, if the mutual contact area is small, the spark is liable to fly, and the contact area increases in the passage welding process, so that even if a large void is generated, the current is increased. Is constant In other words, since the current does not decrease, the spark is scattered, and at that time, the welding lead may be scattered and adhered between the cathode plate and the anode plate of the electrode group to cause a short circuit. Bring. In the constant voltage control method, if the contact area is small, a spark is generated at the start of energization, and in the welding process, the contact area increases, and therefore, the current increases and a void occurs. When a spark is generated, a short circuit similar to that described above may occur due to the scattering of the welding lead, and on the other hand, poor welding is caused.

Disclosure of the invention

 The present invention provides a resistance welding method for a lead-acid battery that has solved the above-mentioned problems of the conventional resistance welding method.The present invention provides a method for energizing members to be welded to each other with their opposing surfaces pressed against each other. In a resistance welding method for a lead storage battery in which mutual contact surfaces are resistance-welded, current is applied between both members by a constant power control method to perform mutual welding.

 In the constant power control method of the resistance welding method according to the present invention, a resistance value during energization between the two members is measured, and the measured resistance value is input to a constant power control device. The method is characterized in that a current having a current value set in accordance with the above is supplied between the two members at regular intervals.

Further, the present invention provides an excellent welding method that eliminates the problem of spark generation at the start of energization in the conventional resistance welding method. It provides a resistance welding method for a lead-acid battery, and gradually increases the flow rate from the start of communication between both members to several cycles before the constant power control method is performed. '/ The present invention provides a resistance welding circuit device in a lead-acid battery for carrying out the above-described resistance welding method of the present invention, so that members to be welded to each other are provided. And a pair of resistance welding guns that press the surfaces facing each other and press-contact in this state, a resistance measuring device that measures the electric resistance (Queen) in a press-connecting state between the members to be welded, and the resistance measurement. And a control current set by the constant power control device, and the control current set by the constant power control device is applied between the members to be welded through the resistance welding gun of the welding machine. Toss .

 Further, the present invention provides an apparatus that uses this apparatus to prevent sparks from occurring at the start of energization and to assure excellent welding when implementing the resistance welding method of the present invention. In the apparatus according to the present invention, the constant power control device is configured such that the passage is gradually increased from the start of the passage to several cycles, so that the upslope control passing between the members to be welded is performed. Equipped with a device,

As described above, according to the present invention, the resistance welding is performed between the materials to be welded by the constant power control method. Since current welding is performed in a constant state, stable welding between both members is ensured. Done. In the welding process, the resistance value between the two materials is measured at every fixed cycle such as every half cycle, and based on this measured value, energization having a current value corresponding to this is performed. Welding with constant power is performed. In this case, when energization is performed by the upslope control that gradually increases the power value over several cycles from the start of the resistance welding, the generation of sparks at the time of initial application is prevented.

 BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is an overall view of one example of an apparatus for carrying out the method of the present invention, FIGS. 2 to 4 are side views of a cut portion of a welding point showing a welding process of one example of the present method, and FIG. FIG. 6 is a graph of a current waveform in the constant voltage control, and FIG. 6 is a graph showing a state of a change in welding current in one example of the constant power control method when the up slope control is applied to an initial stage of power transmission. It is a graph.

BEST MODE FOR CARRYING OUT THE INVENTION

 Next, embodiments of the present invention will be described with reference to the accompanying drawings.

 FIG. 1 shows an example of a resistance welding circuit device for implementing the resistance welding method of the present invention. In the drawing, reference numeral 1 denotes a welding machine including a welding transformer 2 and a pair of clamp-type resistance welding guns 4 connected to lead wires 3 specially provided from the welding transformer 2. The pair of welding guns 4, 4 are linked to each other by the expansion and contraction of a pressure cylinder 5 provided on the side thereof, and are opened and closed about a pivot 6 thereof.

Furthermore, both ends of the welding guns 4 and 4 were supported by columns. According to the present invention, the welding resistance can be provided on the lab surfaces of the welding guns 4 and 4 by providing the welding resistance measuring terminals 9 and 9 in such a manner that the lifting resistance is provided by a lifting cylinder 8 vertically mounted on the mounting beam 7. These are connected to the resistance measuring device 11 via the connection codes 1 G and 10, and the output power of the resistance measuring device 11 is connected to the constant power control device via the connection line 12. 13, and the output lavage of the constant power control device 13 was connected to the welding transformer 2 via a connection line 14. The operation of the resistance welding circuit device A thus configured according to the present invention will be described below.

The cells in the cell chambers c and C- in the lead-acid battery B disposed below the resistance welding guns 4 and 4! ), E.e., e-shaped welded members e, e projecting upward from one end of straps S, S of opposite polarities through the partition wall P of b). In order to resistance-weld the ears to each other through the through-hole h provided in the partition wall P, first, the resistance welding guns 4 and 4 are lowered, and as shown in FIG. The protruding projections ，, f are positioned close to the outer surface of the plate-shaped ears e, e arranged opposite to each other so that the protruding projections 突出, f are aligned with the through-hole h, and are arranged inside the plate-shaped ears e, e; From this state, the pressurized cylinder 5 is operated, and the opposing plate-like ears e, e on the inner side thereof are clamped from the outer surface by the pair of welding guns 4 and 4, and pressurized to form a plate-like shape. The inner surfaces of the ears e and e are pressed against the outer peripheral surface of the through hole h of the partition wall P in a liquid-tight manner, and the center of the inner surface of the plate-like ears e and e is formed by the through holes h without the protrusions f and e. Into each other and Occupies not crimp the center facing surface of the (Figure 3). This In this state, an alternating current from the welding transformer 2 connected to the power supply is supplied between the lugs e, e in the pressed state via the pair of resistance welding guns 4, 4 to start resistance welding. At the time of energization, the welding guns 4 and 4 of the pair are provided with welding resistance measuring terminals 9 and 9 in advance, and through this, a welding resistance measuring device 1U is used to connect the plate-shaped ears e and e. The resistance value of the press-contact surface is measured, and this measured resistance value is input to the constant power control device 13. Thus, based on the resistance value R, the constant power control device 13 outputs a signal of a predetermined current value I corresponding to the measured resistance value R from a predetermined power W, and outputs the signal to the welding transformer 2. Tell A current corresponding to the current value I is supplied between the plate-shaped ears e through the resistance welding guns 4. In this case, the measurement of the resistance value, and thus the constant power control, is performed such that a half cycle is performed in a constant cycle such as one cycle. In the case of half-cycle control, the resistance value R is measured by the above-mentioned resistance measuring device 1U in the half-cycle with alternating current, and the constant power control device corresponding to this resistance value is measured in the next half-cycle. The plate ears e, e are energized by setting the current value I according to Fig. 13.Similarly, in the next half cycle, the welding between the plate ears e, e during energization is good. To end. Immediately after the completion, as shown in Fig. 4, the resistance welding guns 4, 4 are separated from both ears e, e. As is apparent from FIG. 4, the pressed members e 1 and e 2 have their press contact surfaces fused with each other to obtain a strong connection. More specifically, the constant power control method of the present invention is applied to the half cycle control of the above embodiment. In the constant power controller 13, based on the measured resistance value R after each half cycle, the current of W (−constant) = I determined by I and R is obtained. When the next half cycle is subjected to phase control (that is, control of energization time), energization control is performed as shown by a very oblique portion in each half cycle as shown in Fig. 5, for example. The constant power control device 13 is set so as to apply a constant force of 2 ^. When 50,000 GA flows in a half cycle at the start of energization, the constant power control device 13 has a resistance between the ears e: e. anti value measured by the resistance measuring device 1 1, the value 0.78 of the measured value R. at that time <. 1 0 one ⁴ Omega is inputted to the constant power control device 1 3, based on this value, the apparatus 13, a current of approximately 5,600 A is caused to flow between the plate-shaped ears e, e in the next half cycle, and the next half-cycle is performed based on the measured resistance value R at this time. The energization amount I of the vehicle is set, and electricity is applied between the plate-shaped ears e and e. In this way, a total of 10 cycles of electricity are applied by the constant power control method, and the plate-shaped ears e and e are energized. According to the present invention, according to the present invention, the resistance between the members to be welded e, e is measured at regular intervals from the start of passage, in this example, every half cycle, and based on this, weld members _e:. since the constant power control scheme in earthenware pots by being energized energizing location to between e is set Ri by the predetermined constant power value, the resistance with increasing service I cycle number弒少In addition, if the amount of current increases in addition to this, and a void is generated at the end, the resistance increases, but the amount of traffic increases, so that the conventional method is used. The current drops even when a void occurs. As a result, a spark is generated, and as a result, it is possible to prevent the welded portion from being defective, and to stably and well perform the welding.

 In the conventional constant current or constant voltage control method, there is a dislike for generating a spark at the start of the energization. In particular, both ears e, which come into contact through the circular through hole h of the partition wall P of the battery case, This is likely to occur when the diameter of the circular contact surface where e initially comes into contact is approximately 2ππη or less, and as a result, the rejection rate of the final welded state becomes extremely high.

In the present invention, when resistance welding is performed by the constant power control method, resistance welding is performed by applying a relatively small current at the start of the current supply, and subsequently, the constant power control method is used. Therefore, even if the diameter of the hole h of the partition wall の is 1 to 2 nun as described above, welding is performed without generating a spark, and a completely defective welded portion is not formed at the welded portion. It was confirmed that no welding was obtained. That is, according to the present invention, there is provided a resistance welding method characterized by applying an up-slope control current between the members to be welded e and e before performing the constant power control method. In order to carry out this method, an up slope control device 15 is incorporated in the resistance welding circuit device A. As shown in the figure, it is common to incorporate an up slope control device 15 into the constant power control device 13 of the device A. _{ft The} constant power control device 13 and the up slope control device 1 (5) Known methods for It can consist of steps. The up slope control 15 outputs a stepwise increasing current signal, and the current of the welding transformer 2 is determined by the signal. This is achieved by controlling the conduction time of the thyristor using a thyristor or the like. For example, the up slope control device 15 causes the welding transformer 2 to intervene between the plate-shaped ears e 1 and e via the pair of guns 4 1 and 4, and the first cycle to start energization. In the current cycle, a relatively small current of 1,500 A flows, and the current of 3,500 A is automatically generated in the second cycle, and the current of 4,500 OA is automatically generated in the next third cycle. When the current is gradually increased, the resistance welding proceeds gradually without any spark. Next, from the fourth cycle, the constant power control (2 kw) is switched to the 50,000 OA communication, and the constant power control is performed until the 10th cycle, thereby completing the welding operation. In this case, the electric power in the up-slope control is increased stepwise to 0.5 kW for the first cycle, 1 kW for the second cycle, and 1.5 kW for the third cycle. To FIG. 6 shows a stepwise increasing state of the amount of energization when the above-described up slope control and constant power control are continuously performed. When the up-slope control is applied in advance, the welding between the ears e, e by the constant power control method of the present invention is performed even if the diameter of the initial contact area between them is 2 or less as described above. Generally, no spark is generated and the welded portion can be completely welded to obtain a high quality welded portion.

Next, a comparative test between the present method and the conventional method is shown. A lead with 8 internal diameters of circular through-holes formed in a partition wall of about 1 mm thickness that separates the cell chamber of the battery case, and protruding upward from one end of a strip of opposite polarity on each side. Cell made of alloy A pair of electrodes with indirectly mounted plate-shaped ears facing each other and a pressurized projection at the center of the inner surface, that is, a pair of opposite polarity strip plates opposed to each other by a resistance welding gun The ears are pressurized from the outer surface thereof to be pressed against the peripheral surface of the through hole of the partition wall in a liquid-tight manner, and the center part of the opposing ear is pushed into the through hole by the pair of pressurizing protrusions and pressed against each other. . In this way, as shown in the table below, a large number of seven types of rechargeable batteries in the first press-contact state from 1 m to 7 mm were prepared, as shown in the table below. Conventional constant current control method, constant voltage control method, constant power control method without upslope (U.S.) and constant power control method with upslope (U.S.) for storage battery Resistance welding was performed, and the gap between the ears was welded. The results were as shown in the table below. The welded part was cut and the welded surface was found to be defective if there was at least one unwelded joint, and the welded surface was found to have no unwelded part, ie, completely welded. The percentage (%) shown in the table means the proportion of good samples out of a large number of predetermined samples in each welding method. -: Contact part i Constant current I Constant voltage '! Constant power; ϋ. S. 3∞-'s 'house: 6 A> 0.4 V kw'! Constant electric sword 2 '

!

 'i ^ 10%! 10% 50%! 1 0 0%

• I

5 0 '5 0 9 0 1 0 0-y then ¹ ! 90 u u! 1 0 0. *

 100: 100! 1 0 0: 1 0 0

 1

 6: 1 0 0 1 0 0: 1 0 0 ': 1 0 0

-6: 9 0 9 0 i 1 0 0 1 0 0

10 0 9 η 0 As is clear from the above table, the constant power control method of the present invention has a particularly small contact area between the members to be welded as compared with the conventional constant current and constant voltage control method. This is effective when the size is relatively small. In this case, it is useful to apply the key / pump control at the beginning of energization. The gap between the ears is completely welded regardless of the contact area.蓄 QQ% of batteries with good quality can be obtained. In the above embodiment, the case where the members to be welded e and e are the strip polar ears has been described. However, other lead alloy members constituting a lead-acid battery curved plate, for example, a strap It can also be used for welding the terminal to the electrode plate for terminals.

As described above, according to the present invention, the members to be welded of the lead storage battery are welded by the constant power control method, so that the members are always constant regardless of the change in the contact area between the materials to be welded. The welding operation can be performed in a stable amount, and in this case, The resistance value between the members to be welded is measured every time, and based on the measured resistance value, when the next energizing current is controlled via the constant power control device to perform welding, the The accuracy of stable and high-quality welding is increased, and a relatively small flow rate is gradually increased by the up-slope control in the initial stage of energization in several cycles. Has effects such as being able to perform complete welding without spark generation. Industrial applicability

 As described above, the present invention can be used very effectively in manufacturing a lead-an battery.

Claims

The scope of the claims  1 ・ In the resistance welding method for lead-acid batteries in which the members to be welded to each other are energized while the opposing surfaces are pressed against each other and the mutual contact surfaces are resistance-welded, a constant power control method is used to A resistance welding method for lead-acid batteries, characterized in that the two are welded to each other.  2. In the constant power control method, a resistance value when power is supplied between the two members is measured, and the measured value is input to a constant power control device, and the device responds based on the measured resistance value based on the measured resistance value. The resistance welding of the lead-acid battery according to claim 1, wherein a current having a set current value is supplied between the two members at regular intervals. Law.  3. Before performing the constant power control method in the welding method described in Claim 1, perform an up-slope control to gradually increase the amount of current for several cycles from the start of current application to both members. Resistance welding method for lead-acid batteries, 4. To be welded to each other-a pair of resistance welding guns (4), (4) and (4), A resistance measuring device (11) for measuring an electric resistance value in a press-contact state between the members to be welded (e) and (e); and a constant power control device connected to the resistance measuring device (11). And the constant power control device The control current set by the position (13) is applied between the members to be welded (e) and (e) via the resistance welding guns (4) and (4) of the welding machine. And a resistance welding circuit device. 5. The resistance welding circuit device according to claim 4, wherein the members to be welded are gradually increased from the start of energization to several cycles. Resistance welding circuit device with an up slope control device (15) that energizes between.